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    Electron Neutrinos From Muon Neutrinos!
    By Tommaso Dorigo | June 15th 2011 07:08 AM | 48 comments | Print | E-mail | Track Comments
    About Tommaso

    I am an experimental particle physicist working with the CMS experiment at CERN. In my spare time I play chess, abuse the piano, and aim my dobson...

    View Tommaso's Profile
    New results from the T2K collaboration have been presented at a KEK Physics Seminar today, and they are really interesting stuff. In a nutshell, six electron neutrino events have been seen by their far detector, illuminated by a pure and intense beam of muon neutrinos. The estimated backgrounds from non-oscillating-neutrino sources are estimated to amount to 1.5+-0.3 events, and the observed counts thus constitute a 2.5-standard-deviation effect, hopefully a first hint of direct detection of nu_mu -> nu_e oscillations.

    If you are a veteran in particle physics, you seldom get excited by 2.5 sigma results. But this one should be singled out: it represents in my opinion a solid evidence of the oscillation process. To explain why I believe this result will be confirmed with additional data collected by T2K, I need to show a few figures from the seminar.

    First of all, what is T2K ? It is an experiment in Japan which uses the superkamiokande detector to detect neutrinos shot at it from an intense proton beam produced at a facility located xxx km away. The protons are impinged on a target and from the resulting hadrons a beam of neutrinos is extracted. Muon neutrinos, that is: the technology to produce intense beams of these particles dates back to the late sixties and early seventies, when neutral currents were still only the dream of a few visionaries, among them Glashow, Salam, and Weinberg.

    Indeed, neutrinos are surprisingly important particles -they were there when charged-current weak interactions were first figured out by Fermi in the thirties; they were there when the Z boson was first indirectly seen in neutral current bubble chamber exposures. Neutrinos were there at LEP, when the invisible Z decays allowed to figure out that three is the magic number of light generations of matter fields.

    And of course, neutrino physics is central today in High-Energy Physics, with the puzzles it presents. While the LHC is running at full steam and still gives no indication that any new physics will ever be found at the high-energy frontier, many smaller endeavours around the world are patiently collecting neutrino signals from the cosmos, from the atmosphere, from the sun, and from accelerators. The understanding of fundamental physics we may hope to achieve from these experiments is big, and the chance is much larger -we know that there is a lot to measure and study which we have not figured out yet in neutrino physics!



    Now, let me not divagate further. The proton beam of J-PARC, in Tokai, sends neutrinos 295 km away to the Kamioka mine (see above), the burial site of the large water tank which first observed neutrino oscillations. The statistics analyzed this far corresponds to 1.4 E20 protons on target -the funny but effective unit of measurement used in accelerator neutrino experiments to size up the data. Protons interacting with the target produce pions, which decay into muons and muon neutrinos. The latter traverse first a "near detector", which is important for flux normalization and to reduce beam-related systematic uncertainties; and then travel underground to the Kamioka mine, where few of them produce detectable interactions in the large body of water making up the SK (SuperKamiokande) detection element.

    What happens when a neutrino interacts with water in SK ? The neutrino may interact by charged-current or by neutral-current interactions. Let us concentrate on the former: the neutrino becomes its corresponding charged lepton (a muon, that is), imparting some momentum to the recoiling nuclear target. The charged lepton then travels in water at superluminal speed, producing a ring of Cherenkov photons (sort of a "shock wave") which the photomultiplier tubes of SK are ready to detect. The resulting pattern is a beauty to observe, such as in the picture below.



    One feature of the T2K setup which is worth mentioning is the optimization of the angle of production of the neutrino beam. Since high-energy neutrinos cause annoying backgrounds due to neutral current interactions, while at sub-GeV energy the signal is cleaner, the neutrino beam produced at J-PARC is set up to be emitted "off-axis", i.e. at 2.5 degrees off the direction of the incoming protons as they hit the target. This way, the energy of neutrinos is kept at a values which maximizes the observability of the quasi-elastic charged-current signal.

    The signal of electron-neutrino interactions in SK is extracted by applying a very careful selection of the features of the Cherenkov radiation detected in the tank. Among the backgrounds that need to be separated is the diphoton decay of neutral pions produced in the neutral-current interaction of a muon neutrino. The photons create electron-positron pairs, which produce multiple ring topologies.

    Other cuts involve a fiduciality of the position where the interaction took place, and energy requirements. I cannot discuss these in detail here, and invite the interested reader to have a look at the slides of the seminar.

    In the end, from the number of neutrinos directed at the SK detector, the number of background events which pass all electron-like selection criteria is computed at 1.5 events. Systematics are carefully evaluated and result in a 20% uncertainty on the prediction. And finally, the data is unblinded, and the number of electron-like events observed is six. It is a shame that my flight to Geneva is about to board, because I would be happy to do justice to the very interesting cross-checks and studies that allow T2K to estimate backgrounds and related systematics... Maybe another time. The figure below shows the reconstructed energy of the six final candidates, which well agrees with the shape of the expected electron signal (if oscillations occur).



    Below you can see an event display of one of the six candidates: the nice ring distributes on the surface of the tank and well agrees with the expected shape of an electron Cherenkov signal. This is a beautiful picture, worth the cover of a textbook... Remind it to me in ten years!



    In conclusion, I am happy to see that there are "good" 2.5 sigma effects arising sometimes... For once, I would be willing to bet FOR this to be a real signal. Any takers ?







    Comments

    Bonny Bonobo alias Brat
    'While the LHC is running at full steam and still gives no indication that any new physics will ever be found at the high-energy frontier, many smaller endeavours around the world are patiently collecting neutrino signals from the cosmos, from the atmosphere, from the sun, and from accelerators'.

    And neutrinos are also being patiently collected from nuclear reactors. Tommaso, I may be wrong but I think that if you follow the arrow from your diagram above showing the Japanese neutrinos being beamed through hundreds of kilometres of underground rock, the arrow coincidentally also points to the epicentre of the recent Japanese earthquake.

    There are many neutrino experiments like the K2K and the Super-Kamiokande that have been and are still being conducted in Japan, one which may have been operating coincidentally at the closest town to the Japan earthquake's epicentre when it occurred.

    Recently this article and paper at http://www.technologyreview.com/blog/arxiv/26773/?nlid=4495 was released entitled 'Atmosphere Above Japan Heated Rapidly Before M9 Earthquake' which claims that :- 'Infrared emissions above the epicenter increased dramatically in the days before the devastating earthquake in Japan, say scientists.Geologists have long puzzled over anecdotal reports of strange atmospheric phenomena in the days before big earthquakes. But good data to back up these stories has been hard to come by'.

    'In recent years, however, various teams have set up atmospheric monitoring stations in earthquake zones and a number of satellites are capable of sending back data about the state of the upper atmosphere and the ionosphere during an earthquake'.

    'Last year, we looked at some fascinating data from the DEMETER spacecraft showing a significant increase in ultra-low frequency radio signals before the magnitude 7 Haiti earthquake in January 2010Today, Dimitar Ouzounov at the NASA Goddard Space Flight Centre in Maryland and a few buddies present the data from the Great Tohoku earthquake which devastated Japan on 11 March'.

    'Their results, although preliminary, are eye-opening.They say that before the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck. At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating up.These kinds of observations are consistent with an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism'.

    'The thinking is that in the days before an earthquake, the great stresses in a fault as it is about to give cause the releases large amounts of radon.The radioactivity from this gas ionises the air on a large scale and this has a number of knock on effects. Since water molecules are attracted to ions in the air, ionisation triggers the large scale condensation of water. But the process of condensation also releases heat and it is this that causes infrared emissions'.

    "Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data," say Ouzounov and co. These emissions go on to effect the ionosphere and its total electron content. It certainly makes sense that the lithosphere, atmosphere and ionosphere are coupled in a way that can be measured when one of them is perturbed'.

    'The question is to what extent the new evidence backs up this idea.The Japan earthquake is the largest to have struck the island in modern times and will certainly turn out to be among the best studied. If good evidence of this relationship doesn't emerge from this data, other opportunities will be few and far between'.

    Tommaso, how can we be sure that there is no connection between these man-made neutrino, collider and nuclear experiments and changes in the geomagnetosphere, the lithosphere, the atmosphere and the ionosphere which are coupled in some way that we don't yet understand?
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Mostly because the article plainly states: "... has detected 6 electron neutrino candidate events based on the data collected before March 11, 2011"? It also doesn't state that the 6 events were all recorded on March 10, which might have alluded to interference by the lead-up to the quake.

    Bonny Bonobo alias Brat
    Isn't that because the facility was either damaged or at least adversely impacted by the earthquake? Prior to this the T2K experiment described here at http://arxiv.org/PS_cache/arxiv/pdf/1106/1106.1238v2.pdf and the Super-Kamiokande websites were usually updated more frequently. According to this press release by J-PARC at http://www.kek.jp/intra-e/press/2011/J-PARC_T2Kneutrino.html

    'Based on the analysis of all data collected by the T2K experiment between January 2010 when it began full operation and March 11, 2011 when it was interrupted due to the great East Japan earthquake, 88 neutrino events were detected by the Super-Kamiokande. Six candidate events cleanly identifiable as electron neutrino interactions were identified out of these eighty-eight events'.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Bonny Bonobo alias Brat
    I'm not asking about the six candidate events in particular, I am asking if these man-made neutrino, collider and nuclear experiments in general and their associated 'missing energy' (see http://en.wikipedia.org/wiki/Missing_energy ) that occurs in the ongoing beam loss, could somehow be correlated to changes in the geomagnetosphere, the lithosphere, the atmosphere and the ionosphere that occurred above the epicentre of the earthquake? Which coincidentally occurred in the same direction as these neutrino beams which were being fired, 1 kilometre deep under the ground in disused mines.

    The paper describing the T2K experiment at http://arxiv.org/PS_cache/arxiv/pdf/1106/1106.1238v2.pdf talks about beam loss, beam loss monitoring along with beam dumps and the high temperature and well insulated graphite target for collecting those beams that don't get lost, but what is happening to the beams that do get lost? The paper states that :-

    'A well-tuned proton beam is essential for stable neutrino beam production, and to minimize beam loss in order to achieve high-power beam operation. Therefore, the intensity, position, profile and loss of the proton beam in the primary sections are precisely monitored by five current transformers (CTs), 21 electrostatic monitors (ESMs), 19 segmented secondary emission monitors (SSEMs) and 50 beam loss monitors (BLMs), respectively'.

    '3.1.6. Beam Loss Monitor. To monitor the beam loss, 19 and 10 BLMs are installed near the beam pipe in the preparation and final focusing sections respectively, while 21 BLMs are positioned near the SCFMs in the arc section. Each BLM (Toshiba Electron Tubes & Devices E6876-400) is a wire proportional counter filled with an Ar-CO2 mixture [14]. The signal is integrated during the spill and if it exceeds a threshold, a beam abort interlock signal is fired. The raw signal before integration is read by the FADCs with 30 MHz sampling for the software monitoring.

    ' By comparing the beam loss with and without the SSEMs in the beamline, it was shown that the BLM has a sensitivity down to a 16 mW beam loss. In the commissioning run, it was confirmed that the residual dose and BLM data integrated during the period have good proportionality. This means that the residual dose can be monitored by watching the BLM data'.

    '3.2.5. Target. The target core is a 1.9 interaction length (91.4 cm long), 2.6 cm diameter and 1.8 g/cm3 graphite rod. If a material significantly denser than graphite were used for the target core, it would be melted by the pulsed beam heat load. The core and a surrounding 2 mm thick graphite tube are sealed inside a titanium case which is 0.3 mm thick. The target assembly is supported as a cantilever inside the bore of the first horn inner conductor with a positional accuracy of 0.1 mm.The target is cooled by helium gas flowing through the gaps between the core and tube and between the tube and case. For the 750 kWbeam, the flow rate is ∼32 g/s helium gas with a helium outlet pressure of 0.2 MPa, which corresponds to a flow speed of ∼250 m/s. When the 750 kW proton beam interacts with the target, the temperature at the center is expected to reach 700◦C, using the conservative assumption that radiation damage has reduced the thermal conductivity of the material by a factor of four. The radiation dose due to the activation of the target is estimated at a few Sv/h six months after a one year’s irradiation by the 750 kW beam [15]'.

    '3.2.8. Beam Dump. The beam dump sits at the end of the decay volume. The distance between the center of the target and the upstream surface of the beam dump along the neutrino beam direction for the off-axis angle of 2.5◦ is 109 m. The beam dump’s core is made of 75 tons of graphite (1.7 g/cm3), and is 3.174 m long, 1.94 m wide and 4.69 m high. It is contained in the helium vessel. Fifteen iron plates are placed outside the vessel and two inside, at the downstream end of the graphite core, to give a total iron thickness of 2.40 m. Only muons above ∼5.0 GeV/c can go through the beam dump to reach the downstream muon pit. The core is sandwiched on both sides by aluminum cooling modules which contain water channels. The temperature in the center of the core is kept at around 150◦C for the 750 kWbeam.'

    '3.2.6. Magnetic Horn. The T2K beamline uses three horns. Each magnetic horn consists of two coaxial (inner and outer) conductors which encompass a closed volume [16, 17]. A toroidal magnetic field is generated in that volume. The field varies as 1/r, where r is the distance from the horn axis. The first horn collects the pions which are generated at the target installed in its inner conductor. The second and third horns focus the pions. When the horn is run with a operation current of 320 kA, the maximum field is 2.1 T and the neutrino flux at Super-Kamiokande is increased by a factor of ∼16 (compared to horns at 0 kA) at the spectrum peak energy (∼0.6 GeV)....They are optimized to maximize the neutrino flux; the inside diameter is as small as possible to achieve the maximum magnetic field, and the conductor is as thin as possible to minimize pion absorption while still being tolerant of the Lorentz force, created from the 320 kA current and the magnetic field, and the thermal shock from the beam'.

    Are the 'lost beams' hitting material beyond the Super-kamiokande target, material that is significantly denser than the graphite used for the target core, that was then melted by the pulsed beam heat load? Could this activity have somehow been related to the rapid increase of emitted infrared radiation that was observed from the satellite data on March 8th and for 3 days before the earthquake? Emissions that somehow then went on to effect the ionosphere and its total electron content?
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Happily, Helen, you're way off the mark.
    The proton beams are produced hundreds of kilometres from Super-Kamiokande. They get smashed into a block of graphite, which produces (among other things) pions and kaons, the decays of which give the neutrinos. None of the charged stuff produced in these interactions makes it anywhere near Super-Kamiokande, as it can't propagate far through rock...

    It goes without saying that the neutrino beam itself can't possibly cause something as dramatic as an earthquake. A local farmer hammering in a fence post would have a much greater effect.

    Bonny Bonobo alias Brat
    Thanks Rhys for your reassuring words, however I didn't specifically ask if the neutrino beam can cause an earthquake? I asked if the T2K experiment is creating something that could possibly be correlated with the fact that just prior to the earthquake on March 11th the total electron content of the ionosphere inexplicably increased dramatically over the relatively nearby earthquake epicentre, reaching a maximum three days before the quake struck.

    According to the T2K website at http://jnusrv01.kek.jp/public/t2k/node/2 and this T2K experiment article that it links to at http://jnusrv01.kek.jp/public/t2k/sites/default/files/KEK110613english.pdf :-

    'When electron neutrinos interact with matter, electrons are produced. However, electrons are also observed with some probability in background events other than the electron neutrino appearance. In the current T2K experiment, 1.5 such background events were expected to be detected and thereby the probability of the existence of electron neutrino appearance is estimated to be 99.3%*7, suggesting the appearance of electron neutrinos for the first time'.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Hank
    Of course you did.   95% of your comments are to create some non-science/conspriacy point or another.  Your first comment was "Tommaso, how can we be sure that there is no connection between these man-made neutrino, collider and nuclear experiments and changes in the geomagnetosphere, the lithosphere, the atmosphere and the ionosphere which are coupled in some way that we don't yet understand?"

    What????  How can we be certain you are not a strangelet from the future who sent itself back in time to keep the LHC from being built so it can't cause big earthquakes??  But, wait, if you prevent yourself from being created, you can't keep yourself from ruining Earth.  Oh, the paradox!

    And now you seek to say you aren't engaging in your usual kookiness by qualifying it with "I didn't specifically ask if the neutrino beam can cause an earthquake" - though it is absolutely the nonsense you are promoting once again.
    Bonny Bonobo alias Brat
    '95% of your comments are to create some non-science/conspiracy point or another.  Your first comment was "Tommaso, how can we be sure that there is no connection between these man-made neutrino, collider and nuclear experiments and changes in the geomagnetosphere, the lithosphere, the atmosphere and the ionosphere which are coupled in some way that we don't yet understand?"'

    Hank, how can the phrase 'which are coupled in some way that we don't yet understand' imply a conspiracy? Also, if most of my comments are 'non-science' then I'm very sorry, but I am doing my best to try to understand the science involved in generating electron neutrinos and also in generating earthquakes, as are many scientists I believe.

    The scientific paper at http://www.technologyreview.com/blog/arxiv/26773/?nlid=4495  entitled 'Atmosphere Above Japan Heated Rapidly Before M9 Earthquake' claims that infrared emissions above the epicenter increased dramatically in the days before the devastating earthquake in Japan and just before the M9 earthquake, the total electron content of the ionosphere inexplicably increased dramatically over the epicentre, reaching a maximum three days before the quake struck.

    'At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake and the atmosphere was heating up', an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism.  I was simply wondering if there could be some connection between the T2K experiment simultaneously generating trillions of electrons and electron neutrinos relatively nearby and a big increase in the total electron content of the ionosphere above the soon to be, earthquake epicentre. How does asking these questions make me completely kooky? If they do then surely they should be easy to dismiss or prove wrong?

    'In 1985 Mikheyev and Smirnov, following Wolfenstein, developed the idea that the oscillations of neutrino flavors might be resonantly enhanced on their way through matter due to their coherent elastic forward scattering off electrons, which adds to the vacuum propagation phase changes (the MSW effect). The neutrinos of all flavors scatter via neutral current interactions while only electron neutrinos scatter additionally via charged currents'. See http://arxiv.org/ftp/physics/papers/0503/0503172.pdf
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    I was simply wondering if there could be some connection between the T2K experiment simultaneously generating trillions of electrons and electron neutrinos relatively nearby and a big increase in the total electron content of the ionosphere above the soon to be, earthquake epicentre. How does asking these questions make me completely kooky? If they do then surely they should be easy to dismiss or prove wrong?

    Rhys answered this above. The charged particles produced along with neutrinos at the accelerator can't go anywhere -- they are absorbed by the walls around the target and return to ground (the Earth). The tiny, tiny, tiny, tiny, tiny, TINY fraction of neutrinos in the beam that interact with the Earth along their path don't produce anything that escapes into the atmosphere, and nowhere near the amount charge referred to in that paper. Really, the probability of neutrinos interacting with everyday matter (i.e. atoms) is unimaginably small. There are literally trillions upon trillions upon trillions of neutrinos constantly passing through the Earth (from the Sun and other sources) without interaction. And the beam in the T2K experiment is made of the same stuff.

    When members of the boards get annoyed and think you are trolling, it's because this aspect of the physics is quite well understood, and your responses imply that you refuse to believe it for some reason.

    Bonny Bonobo alias Brat
    Well actually that's the best explanation anyone has bothered to give me so far but it would be nice to also have a link to this aspect of physics that is 'quite well understood'. Also, it is interesting that you feel that you have to remain anonymous.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Gerhard Adam
    You just never learn ... oh well, suit yourself.
    Mundus vult decipi
    Bonny Bonobo alias Brat
    Sorry Gerhard, not sure what you mean? I am trying to learn.

    Members of the boards, I'm not trolling, I really just want to understand what's going on here and put my mind at rest. I've worked for many years in big companies as an IT/business systems analyst/programmer consequently I have very little faith in any one person in any large organisation fully understanding the big picture. I have also written plenty of executive summaries for executives sitting on boards, who are in charge of making the big decisions about risks and future directions. I guess I'm just not as trusting as most people of scientists and those on the boards who control them, see http://www.youtube.com/watch?v=zLFRIiflSgU&feature=related
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Gerhard Adam
    If you're trying to learn, then ask questions without innuendo.  In your two simple sentences you managed to cast doubt on the comment by putting quotes around "quite well understood", which clearly indicates that you are questioning either the statement or the honesty of the poster.

    How would you take it if I said you were the "mother" of teenagers?  Get the drift?

    Your second sentence implied some nefarious reason for the poster being anonymous despite numerous anonymous posts on a regular basis.  If you didn't mean anything by it, then why did you say it?  It wasn't necessary and added nothing to your question, so I can only conclude that you did mean something by it, which is why I said ... you never learn.

    After all, is it "interesting" that you "live" in Australia and are asking these kinds of questions?
    Mundus vult decipi
    My name is Ben. I'm not hiding anything -- this information just isn't controversial. :)

    The first experiment to measure this property of neutrinos is described here:

    http://en.wikipedia.org/wiki/Neutrino_experiment

    Every neutrino experiment since then has confirmed this. They're really quite shy. No need to fear them! So we don't really like to be accused of covering things up, which you sound like you're implying. A lot. Please be nice.

    Bonny Bonobo alias Brat
    So we don't really like to be accused of covering things up, which you sound like you're implying. A lot.
    I have never implied that anyone is covering anything up, quite the opposite, by saying this you lose credibility with me. Thanks for the link to Wikipedia Ben :)

    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Gerhard Adam
    It's interesting that as a "female" you are denying the comment and yet you end with a smiling emoticon?   ... and then you thanked him.
    Mundus vult decipi
    Bonny Bonobo alias Brat
    He asked me to be nice, so at least i can do that :) Now this is interesting,
    new types of fundamental forces in nature being created in particle collidors see
    http://www.sciencedaily.com/releases/2011/03/110328101306.htm
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Hank
    Why is it interesting?  You just cited a generic press release written by a marketing intern at a university about the exact thing the physics expert writing this article is talking about.  Did you even read this article?
    Bonny Bonobo alias Brat
    Interesting because it quite honestly says :-

    'While B mesons were common after the Big Bang, they are not believed to occur in nature today and can only be created and observed under experimental conditions in the LHC or other high-energy colliders. Because these particles don't play by the same rules of physics as most other matter, scientists believe B mesons may have played an important role in the rise of matter over antimatter. The particles may also provide clues about the nature of the forces that led to this lack of symmetry in the universe'.

    "We want to figure out the nature of the forces that influence the decay of these [B meson] particles," Stone says. "These forces exist, but we just don't know what they are'.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Bonny Bonobo alias Brat
    This article here at Science20 about the MINOS neutrino experiment also describes the atmosphere above the neutrino experiment being observed to be 'heating up', though it doesn't claim that there is any correlation between the experiment and the atmospheric event. See http://www.science20.com/welcome_my_moon_base/minos_neutrinos_and_iron_m...

    'This means that the temperature of the stratosphere was increasing dramatically (in some places as much as 40° C) for short periods of time. When they compared the data with meteorological observations of the atmosphere, they found that they were observing a phenomenon called sudden stratospheric warming. Now, potentially, they can use cosmic ray data to detect and measure these warming events'.
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Gerhard Adam
    You got it backwards
    Mundus vult decipi
    "how can we be sure that there is no connection between these man-made neutrino, collider and nuclear experiments and changes in the geomagnetosphere"

    In order to "be sure", we would first have to know 1) what these connections might be and 2) have a plausible model about how these connections might work.

    I would surmise, there are no connections. Neutrinos are called "ghostly" because they are hard to interact with. This universe is basically a neutrino bath [mostly low-energy though] and no-one notices! The solar neutrino flux on Earth is 6.5×10^10/cm²/s [of 0.42 MeV each... bah!]. Supernovas are giving off serious burts [which can be detected in neutrino detectors from light years away], then there is the Big Bang neutrino remnant [100/cm³ of low-energy neutrinos]

    Yes, this is a great result. Thanks for pointing it out.

    Now, this is the first evidence for a nonzero \theta_13 angle in the neutrino mixing matrix. Previous experiments only were able to put upper limits on this value. If this is true, it also opens the possibility to observe CP violation in neutrinos someday in the future.

    P.

    Their vertex distribution looks a little worrying, since all their candidate events pile up on the upstream edge of their detector. More data will tell, however.

    Yes this is annoying even though they spend time (see slide 54) to check this point.

    Unfortunately, due to the earthquake, we have to be patient for a long time.

    Sorry, Tommaso, but this text is kind of missing the whole context. Why are the electron-tau and muon-tau the only oscillations to expect, why can't you get electron-muon neutrino transmutation from the previous two, why events like that would be surprising anyway, and don't we really know the neutrino mass matrix already, anyway?

    dorigo
    Hi Lubos,

    of course, for the context and the whole picture I suggest you to visit the reference frame.

    Cheers,
    T.
    There is manifestly nothing about this particular issue over there so you may have failed as a linker, too. ;-)

    Looking at their slides, I don't see how you can possibly have an informed opinion either way. Those systematics look awfully tight. You gamble too much. So, if it is true, doesn't this weaken the case for the (popular) sterile neutrinos?

    dorigo
    Hi Kea,

    as one who just lost a bet with me, your evaluation of my gambling being reckless isn't carring that much weight ;-)
    If steriles are popular that's not my problem... I think that a simple counting experiment, which predefined their goals and search strategy, and finds 2.5 sigma excess must be considered very interesting -these 2.5 sigma equate to almost 4 sigma of some of the fishing expeditions you usually see in HEP, where the look-elsewhere effect is large.

    Cheers,
    T.

    Did I lose a bet? Has the task force completed its mission already? Yes, perhaps I did, although I might note that I did not actually put up any of my own money. I agree that this result is very interesting. It means we can add a third R2 factor to the neutrino mixing matrix, like for the quarks.

    dorigo
    That's right, you did not lose it yet... And no money is involved, true. We'll have to wait a bit more, but I am so sure of the result that I have started to call it a won bet already.

    Cheers,
    T.
    And they pay you to do science?

    This was really interesting, Tommaso, although what I would really like to see is a mu -> e + photon event ... :-)

    dorigo
    Yes!
    T.
    Is this something new or is it a confirmation of the standard model?

    dorigo
    Well, that depends. The Standard Model has null mass of neutrinos; but it is not hard to extend it to accommodate neutrino masses. This was done in 1998. Now an extended neutrino mixing matrix will be all it takes to insert the observed phenomenon.
    In other words, this is something new but not altogether too unexpected. I would not call it "new physics", in the sense that those words usually take.

    Cheers,
    T.
    I agree with you this is not "new physics" in usual sense of the expression, but people tend to underestimate a bit what' s at stake here. Neutrino oscillations are not dealing with something as precious as a degree of freedom of the model (like the Higgs) but is a proof that conservation of lepton family number is not an exact symmetry. This is one of the reasons I am interested in mu -> e + photon event. It would also not be "new physics" in the traditional sense but it would change the model to a certain extent that is likely just the top of the iceberg...

    all events arise close to border of the fiducial volume. Curious...

    T - not being terribly deep on neutral current interactions, I wonder if there is any theoretical estimate of the range over which oscillations would be seen and if this has factored into the location of the detector in any way. If not, would it not make sense to run two or three detectors in the same beam line?

    dorigo
    Hi anon snowboarder,

    indeed there were bounds and preferred values for the mixing angle which governs these transmutations, and the baseline of the experiment -the distance between far and near detector- was a good match with the expectations for where the effect would be detectable.
    Of course, the more points along the neutrino flight path you have, the more you can understand about the phenomenon; but a near/far configuration such as the one chosen in this case is a good investment.
    Please note that T2K will soon collect a much larger statistics than the one they got so far. This will enable a lot of precision studies. The physics of the neutrino sector is still largely unexplored...

    Cheers,
    T.
    "doing my best to try to understand the science involved in generating electron neutrinos and also in generating earthquakes, "

    If what you'd like to understand is the relation between electron neutrinos and their generation on the one hand, and earthquakes on the the other one, that's easy. There's absolutely no relation at all.

    Actually, Sumar, this is incorrect. The black hole at the centre of the Earth is largely responsible for earthquakes, and understanding the presence of this black hole has a great deal to do with black holes in M theory and the theory of neutrinos.

    Your bong, sir (or madam, as the case may be)

    Carl and Paolo said substantially what Kea said in her blog:
    "... all candidate events occured in one region of the Superkamiokande tank ..."
    based on the information in slide 54 of the T2K presentation by Ken Sakashita, a copy of which I put on the web at
    tony5m17h.net/T2Ktheta13.pdf

    The distribution looks very suspiciously anomalous to me, and I may remain suspicious of any nonzero sin22theta13 until the Daya Bay results come in. As to when that might be, I put up a copy of slide 5 of a Daya Bay presentation by Yifang Wang on the web at
    tony5m17h.net/DayaBaytheta13.pdf

    I have added a horizontal black line at the value 0.03 that has been claimed at 2.5 sigma by T2K. You can see from the Daya Bay slide that (if all goes well) the 0.03 value should be either seen (at 3 sigma) or excluded by Daya Bay before the end of this year 2011.

    Also, the Daya Bay slide indicates that T2K will not be able to discover a value of 0.03 at 3 sigma until around 2014 at the earliest.

    That makes me think that T2K is under extreme time pressure from its Daya Bay competitor, and so may be pushing the limits of its capabilites, perhaps neglecting suspicious circumstances as the distribution of the 6 T2K events.

    Tony

    PS - Tommaso, you can put the slide images on this blog if you want to do so. I do not know how to include them in a comment.

    In my previous comment, I should have said:
    "Also, the Daya Bay slide indicates that T2K will not be able to discover a value of 0.03 at 3 sigma until around 2012 at the earliest. "

    The "2014 at the earliest" should refer to the time by which T2K would have a sensitivity limit (90 per cent CL) of 0.03.

    Tony